The department's lawyers concluded that Taliban and Al Qaeda fighters are not protected by the Geneva Conventions (search) because they do not satisfy four main conditions of the treaty itself. Those include requirements to obey laws of war, wear insignia recognizable from a distance and operate under the command of a responsible individual.

Iraqi prisoners are protected under the treaty partly because Iraq (search) is a participating nation in the Geneva Conventions and the United States is an occupying power, a Justice Department official wrote Sen. Patrick Leahy, D-Vt.

William Moschella, assistant attorney general for legislative affairs, said in a letter released Wednesday that despite this important difference, President Bush early in the Afghanistan conflict issued orders that Al Qaeda and Taliban prisoners be treated humanely and consistently with Geneva Conventions principles.

The letter was the administration's latest and most detailed attempt to address increasing criticism from congressional Democrats and human rights activists about what they consider a concerted effort to circumvent U.S. and international laws against torture during the fight against terrorism.

Human rights lawyers took the unusual step of filing a racketeering lawsuit Wednesday against U.S. civilian contractors who worked at the Abu Ghraib prison near Baghdad. The suit alleges contractors conspired to execute, rape and torture prisoners during interrogations to boost profits from military payments.

Some of the new abuse allegations were among the cruelest described within the Iraqi prisons.

One person, identified in court documents only as a prisoner named Rasheed, told lawyers his tongue was shocked and his toenails pulled out. A second person, identified as a prisoner named Ahmed, said he was forced to watch while his 63-year-old father was tortured to death.

The suit seeks payments for the alleged victims and a ban on future government contracts for Titan Corp. of San Diego and CACI International Inc. of Arlington, Va., whose employees worked as government interrogators and translators.

Titan spokesman Wil Williams called the lawsuit "frivolous" and noted that the government has not accused any of its employees of abuse. "Titan never had control over prisoners or how they were treated," Williams said.

CACI called the lawsuit "irresponsible and outrageous" and said the lawyers' allegations were "false and malicious."

"CACI summarily rejects and denies the ill-informed, slanderous and malicious allegations of the lawsuit that attempts to malign the work that we do on behalf of the U.S. government around the world and in Iraq," the company said in a statement.

Also named as defendants are Adel L. Nakhla, a former Titan employee, and two CACI employees, Steven A. Stefanowicz and John B. Israel. All three were implicated in abuses in the investigative report by Maj. Gen. Antonio Taguba.

A series of government lawyers' memos, many of them still secret but leaked to the media this week, said the president had the legal authority to allow torture of detainees during interrogations. Administration officials, however, said such a policy never was adopted.

Democrats and human rights activists seized on the memos as evidence the administration condoned mistreatment.

The conclusions of a March 6, 2003, Pentagon memo that has been made public "are completely at odds with everything Congress has been told about our interrogation procedures, and it raises questions as to whether these arguments contributed to the mistreatment of prisoners in U.S. custody," said Rep. Jane Harman of California, senior Democrat on the House Intelligence Committee.

Harman added that the "extraordinary legal argument" that Al Qaeda and Taliban detainees were not covered by the Geneva Conventions had never been described for her during congressional oversight hearings or on three visits she made to Navy prison camp at Guantanamo Bay (search), Cuba, where more than 600 such detainees are held.

Moschella wrote that the memos constituted proper legal advice to the president about laws regarding torture and about interpretations of international treaties.

"We first want to reject categorically any suggestion that the Department of Justice has participated in developing policies that permit unlawful conduct," the letter says. "The department has done no such thing."

The letter says U.S. officials cannot avoid legal liability for torture by "colluding with officials from other governments" that do approve of harsh interrogation methods. In fact, Moschella said, that would be considered conspiracy to commit torture and could be prosecuted under criminal law.

Yet the letter does not address one of the most contentious assertions in the March 6 memo: that the president, acting as commander in chief, enjoys such "complete discretion" during wartime that U.S. criminal anti-torture statutes may not apply.

"Congress may no more regulate the president's ability to detain and interrogate enemy combatants than it may regulate his ability to direct troop movements on the battlefield," the memo says.

Said House Minority Leader Nancy Pelosi, D-Calif.: "The notion that the law is whatever the president determines it to be is so contrary to our Constitution and our experience as a nation that President Bush should have rejected it out of hand."